The invention concerns a hybrid drive for a vehicle, in particular an automobile, of the type including an electric engine connected with the driving axle of the vehicle and with an internal combustion engine, as well as methods for operation of such a hybrid drive.
Hybrid drives of this kind are known, e.g., from German Letters of Disclosure No. 21 33 485 as well as Swiss Pat. No. 222,098. In comparison with hybrid drives in which an electric motor for driving the driving axle of a vehicle is selectively supplied current from an energy storage device or an electric generator driven by an internal combustion engine, hybrid drives of this kind offer the essential advantage that a single electric engine can be used at the same time as a driving engine, as a generator for charging of the electrical energy storage device or as a starter motor for the internal combustion engine. The internal combustion engine, the electric engine and the driving axle of the vehicle are connected in series when this type of hybrid drive is present. Between the internal combustion engine and the electric engine, on the one hand, and between the electric engine and the driving axle, on the other hand, there are inserted respective disconnecting clutches, whereby, depending on need, none, only one of the two clutches, or both disconnecting clutches are engaged.
The replacement of the flywheel of the internal combustion engine of a hybrid drive, consisting of an internal combustion engine and an electric engine, by the mass of the rotor components of the electric engine, is known from German Letters of Disclosure No. 24 00 760. In this known arrangement, the electric engine is constructed in the form of a built-up rotor motor which acts not only as an electric drive motor, but at the same time takes over the coupling tasks, i.e. it acts as a clutch. Further with this construction the flywheel mass of the electric engine, which collaborates with the internal combustion engine, is integral with the combustion engine-side clutch component of the electric engine so that upon disconnection of the electric engine, when it is acting as a clutch, the flywheel mass always remains connected rigidly with the internal combusion engine.